Transcription factors (TFs) are a group of proteins that regulate gene expression. In humans, they regulate the expression of about 30,000 genes. Their activities are in turn regulated by a number of different mechanisms including interaction with other transcription factors or co-regulators. Because of the large number of transcription factors (total about 2000) and the multitude of interactions among them, the transcriptional regulation network is complex and not yet understood. The answers to a series of important questions about gene regulation all rely on knowledge of the interaction of transcription factors. Therefore, establishing an interaction network of transcription factors is an extremely important task for us to complete before we can understand the mechanism of transcription regulation, uncover the abnormal regulatory processes in human diseases, and develop new therapeutic approaches. Current technologies such as co-immunoprecipitation, supershift, or the yeast two-hybrid system simply cannot meet the requirements for this task due to time consuming and labor intensive operations and problems in reliability. Panomics has developed array-based technologies that allow accurate determination of dual protein interactions as well as simultaneous multiple interactions. Here, we propose a two stage, Fast-Track approach for establishing an interaction network of approximately 20% of the potential transcription factors, 400 TFs. In Phase I, we will establish prototype arrays for protein-protein interactions and for transcription factor interaction in regulatory complexes. We will demonstrate the usefulness of these arrays by probing the interactions of a small number of key transcription factors. In Phase II, we will extend the array format to include the entire set of 400 transcription factors and will use the resulting data to develop a description of the interaction network. In the process, we will perfect the technology for extending the network to the entire complement of human transcriptional regulatory proteins. The objective of this project is to establish a new tool for understanding gene regulation during normal development and disease and to offer to researchers a set of reagents and database products, which are far more powerful than those currently available. [unreadable] [unreadable]